FCC Chairman Julius Genachowski says existing law allows the commission to apply a 'narrowly tailored broadband framework' to ensure that all Internet traffic is handled the same way.

The Federal Communications Commission has come up with a new way to apply some net neutrality rules that would force Comcast Corp., AT&T Inc. and other broadband Internet service providers to handle all Web traffic the same, without imposing limits on users or blocking websites.

Its proposal released Thursday is aimed at blunting an April federal appeals court ruling involving Comcast that found the agency had limited authority to regulate broadband Internet service.

FCC Chairman Julius Genachowski said in a statement that the Comcast decision had created a "serious problem" and that his agency believes more regulation of broadband Internet service is needed, though not the heavier restrictions that apply to telephone companies.

Genachowski, a Democratic appointee to the commission, said existing law allows the agency to apply a "narrowly tailored broadband framework" to regulate Internet traffic.

Previously, the FCC had a nearly hands-off policy regarding Internet service in its effort to spur broadband development. It favored net neutrality — equal access to content that allowed customers to do what they wished with their Internet connections.

But last month, Comcast — the nation's largest cable company and Internet service provider — won a court ruling that said the FCC had overstepped its authority in forcing the company to give its subscribers equal access to all online content providers. Comcast had tried to limit access to some downloading services that used huge amounts of data, slowing communication for others.

"Heavy-handed prescriptive regulation can chill investment and innovation, and a do-nothing approach can leave consumers unprotected and competition unpromoted," he said.

The Republican appointees to the commission, Robert M. McDowell and Meredith Attwell Baker, issued a joint statement slamming Genachowski's proposal.

"After several government investigations, no evidence of systemic failure in the broadband market has been presented to justify this new, more onerous regulatory regime," they said. "Additionally, without a specific mandate from Congress, the appellate courts are likely to hand the commission another stinging rebuke for attempting to shatter the boundaries of its statutory authority."

Comcast, which is currently awaiting FCC approval of a merger with NBC Universal, issued careful remarks that did not directly criticize the proposal.

"We are prepared to work constructively with the commission," Sena Fitzmaurice, Comcast's vice president of government communications, said in a statement. But she said her company would urge the FCC to avoid measures that would "cast the kind of regulatory cloud that would chill investment and innovation."

Another giant Internet provider, Verizon Communications Inc., did not mince words in opposition and hinted that it might take court action if the proposal was approved.

"We believe that the chairman's stated approach is legally unsupported," Tom Tauke, the company's vice president of public affairs, said in a statement. "The regulatory and judicial proceedings that will ensue can only bring confusion and delay to the important work of continuing to build the nation's broadband future."

The FCC will hold a series of public meetings to solicit comments on the proposal, said an agency spokeswoman, before it goes to a vote by the five commission members.